Organic Light Emitting Diode (abbreviated to OLED) is an organic thin film electroluminescent device with the advantages of uncomplicated manufacturing process, low cost, suitable for flexible structure, wide viewing angle and the like. Therefore, OLED based display technology has been an important display technology.
At present, light output efficiency of the OLED is relatively low, generally speaking, only a little amount of light is extracted to the environment. One reason thereof is that when the light from light-emitting layer is incident onto an even surface of a metal electrode, surface plasma electromagnetic waves generated thereby are unable to be extracted to the environment as these electromagnetic waves propagate transversely along the even surface of the metal electrode.